Transfer mechanism for nut forging machine



March 6, 1956 F. B. HATEBUR 2,736,909

TRANSFER MECHANISM FOR NUT FORGING MACHINE Filed April 28, 1955 8Sheets-Sheet 1 I I 'l I 1 o O O I /0 1.3 v 0 5 5 G I :1 II 1" O Q l' O OI .16 (3 o i o 9 O Q (P M O i O .12 E :1, i I. 1 1o 5:; I; l 11INVENTOR. ,1?! B. llaiebur: BY

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TRANSFER MECHANISM FOR NUT FORGING MACHINE Filed April 28, 1955 8Sheets-Sheet 2 N En- J INVENTOR.

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TRANSFER MECHANISM FOR NUT FORGING MACHINE Filed April 28. 1955 8Sheets-Sheet 3 A N n March 6, 1956 F. B. HATEBUR 2,736,909

TRANSFER MECHANISM FOR NUT FORGING MACHINE Filed April ,28, 1955 8Sheets-Sheet 4 IN VEN TOR.

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TRANSFER MECHANISM FOR NUT FORGING MACHINE Filed April 28, 1955 8Sheets-Sheet 8 United States Patent G F TRANSFER MECHANISM FOR NUTFORGING MACHINE Fredrich Bernhard Hatebur, Basel, SwitzerlandApplication April 28, 1955, Serial No. 504,551 Claims priority,application Switzerland May 13, 1950 Claims. (Cl. -76) This applicationis a continuation-in-part of my application Serial No. 201,525 filedDecember 19, 1950, now abandoned.

The present invention relates to a multiple punch press intendedparticularly for the manufacture of nuts and wherein at least two ormore press tools are utilized each consisting of a die and a punch.

An object of the invention is to provide a construction wherein the diesand the guiding sleeves for the punches are arranged upon two oppositemembers of a frame unitary block which is detachably secured to thepress bed in such a manner that the latter takes up the deformationstress.

A further object of the invention is to provide a construction whereinat least one pair of conveyer tongs for conveying the blanks from onedie to the next can reach with its nipper arms from either sideapproximately at right angles to the plane of the block between themembers thereof and be displaceable' from one die to the other in adirection parallel to the members of the block which carry the presstools so that the nippers of the tongs grip the work transverse to thedirection in which the work is conveyed.

A further object of the invention is to provide means for operating thevarious elements of the press synchronously.

With the above and other objects in view which will appear from thedetailed description below taken in conjunction with the drawings, apreferred form of construction is shown therein in which:

Figure l is a partial plan view of a press with the three press toolsshown in cross section;

Figure 2 is a side elevational view of the press with portions shown incross section and showing the conveying tongs in closed position;

Figure 3 is a view similar to Figure 2 showing the conveying tongs inopen position;

Figure 4 is a front elevational view of a portion of the press showingparts in cross section;

Figure 5 is a view similar to Figure 4 illustrating particularly thelateral movement of the longitudinal shafts for the conveying tongs;

Figure 6 is a side elevational view with parts diagrammatically shownillustrating the driving mechanism for the ram for actuating the punchesand the controlling and actuating mechanism for operating the conveyingtongs;

Figure 7 is a cross sectional view with parts shown in elevation alongsection lines 77 of Figure 6 illustrating the controlling mechanism foractuating the tongs;

Figure 8 is a similar view to Figure 6 with parts omitted forgreaterclarity showing particularly in elevation the means for actuatingthe transfer of the conveying tongs from one die to another and Figure 9is an elevational view taken upon section line 9-9 of 'Figure 8 lookingin the direction of the .arrows and showing particularly the-means fortransferring the tongs from one die to the next.

In the various figures of the drawings similar reference charactersindicate like parts.

2,736,909 Patented Mar. 6, 1956 A rigid bed 10 is provided for the pressin which there is located a frame-shaped block 11 of integralconstruction. The block 11 is secured by the bolts 12 to the bed 10 andis provided with semi-cylindrical recesses in which sleeves 15 arepartially inserted. The recesses for the sleeves 15 are provided in thetwo opposite members 13 and 14 of the block 11.

The sleeves 15 partly house the press punches 16, 17 and 1.8 on one handand their respective dies 19, 20 and 21 with appurtenant ejectors 19a,20a and 21a on the other hand. The covers 22, clamp the sleeves 15 inwhich the punches are housed as shown in Figure 2 and the covers 22 aresecured by the bolts 23.

The dies 19, 20 and 21 are similarly held by the covers 24. When thebolts 23 for the covers 22 and 24 are released these conveyers may beraised perpendicularly to the plane of the block 11 so that the punchesand dies may be separately replaced.

The advantage of enhanced accuracy is achieved by the fact that thepunches and dies of the press tools are mounted in a common block madein one piece, because when the block is machined on a jig-boring millthe dies are positioned exactly coaxially with their respective punches.Despite this, each separate press tool in the press described can beindividually replaced, so that the press can be rapidly, and with verylittle preparatory work, rearranged for the production of differentpressings.

The block 11 is mounted on the machine bed 1.0 in such mannerthat thebed takes up the stresses which arise during the pressing operation withthe block '11 itself remaining free of stress and serving merely toguide and to center the press tools. This assures continued accuracy inthe work performed by the press.

As shown particularly in Figures 4 and 5 two shafts 25 and 26 extendparallel to the portion 14 of the block 11 which accommodates the pressdies. The shafts 25 and 26 are mounted on the bed 10 on opposite sidesof the plane of block 11. The shafts are rotatably and axiallydisplaceably mounted.

As shown in Figure 4, coupling members 27 and 34 are keyed to the shafts25 and 26 and two nipper arms 28, 29 and 31, 32 are mounted on theshafts at the ends of said coupling members 27, 34, being spaced adistance apart equal to the distance between the axes of two adjacentpress dies. Said nipper arms 28, 29 and 31,- 32 are connected to thecoupling members 27, 34 by means of flaps 27a, 28a, 29a or 31a, 32a, 34ascrewed together with springs, not shown in the drawing, insertedbetween them. Nippers 30 and 33 are mounted adjustably on each of thearms 28, 29 and 31, 32. The two nipper arms 31 and 32, which areequipped with adjustable nippers 33, are arranged on the shaft 26, andheld against rotation, by means of a coupling member 34 in such a waythat the nippers 30 and 33 are located opposite to one another forpurposes of cooperation.

The nipper arms are so shaped and designed as to be capable of beinginserted between the portions 13 and 14 of the block from both sides ofthe plane of such block and with a movement that is approximatelyperpendicular to the plane of the block.

A crankarm 35 is nonrotatably connected to the shaft 25 and a crank arm36 is similarly connectedto the shaft 26. The crank arm 35 is fixedlysecured to the sleeve 37 (see Figure 5) and the crank arm 36 is'fixedlysecured to the sleeve 38 The sleeves 37 and '38 may rotate upon theshafts 25 and 26 respectively but are held against axial displacementrelative thereto. The sleeves 37 and 38 are fixed to the shafts 25 and26 by means of axially extending splines and slots have joint rotationtherewith. I

A .portion of the shafts 25 and 26 are constructed as a movable splineshaft with the shaft splines 39 extending over such a length of theshafts that they can be displaced axially by a distance separating theaxes of two adjacent dies.

The link members 49 and 41 are connected respectively to the crank arms35 and 36 and at the other end thereof are connected to a two-armedlever 42 pivotally mounted at 61 upon the bed 10.

The system of connecting levers is so designed that when the lever 42 ispivoted by means later to be described the nipper arms 28, 29 and 31, 32with their nippers 30 and 33 swivel towards one another. In other words,the shafts 25 and 26 rotate in opposite directions. One end of a tensionspring 43 is attached to the point of articulation between the lever 42and the link 41 and at the other end is secured to a bolt 44 providedupon the bed 10. The spring 43 tends to actuate the lever system so thatthe nippers 39 and 33 are urged away from one another. A drawbar 62 isattached to the lever 42 at the point 45 and such drawbar is actuated bya mechanism described below. The drawbar can oscillate the lever 42 inthe direction of the arrow P shown in Figure 2 against the action of thespring 43 until the lever 42 encounters the adjustable stop 4-6.

With respect to the drive of the press tools it is pointed out that thedies are stationary. Only the press punches are each moved in known wayby a horizontal eccentric parallel to the punch axis. The shafts whichthese eccentrics drive are connected with the press drive over a gearsystem and a compressed air coupling. The limited opposite rotation ofboth spline shafts 25 and 26 for the opening and closing of the tongs isaccomplished from the press drive over a gear system, line shaftings,bevel gears, a control cam shaft and a lever mechanism to the link 45 asdescribed below. The driving power is shown in Figures 2 and 3 by thearrow P. In Figures 4 and 5 the driving power is similarly indicated bythe arrow Q for the longitudinal movement of the spline shafts 25 and 26which are connected through their extensions 25a and 26a and the yoke 47at the slot 48 to a lever mechanism which furthermore is connected tothe press drive through the medium of a connecting rod. A sliding memberwith a gear segment, a cam disk, a control shaft, bevel gears,connecting shafts and a gear system are described below. The shafts 25and 26 are hollowed out at their ends which carry the coupling pieces 27and 34 and mandrels 51 and 50 engage therein as shown in Figures 4 and 5for the support during the horizontal movement. The mandrels 51 and 56are fixed in the press bed 10.

The opposing nipper arms 28, 31 and 29, 32 arranged opposite each otherin pairs combine so that each pair forms a set of conveyor tongs fortransferring the work from one die to the next.

The principle of operation is as follows: A workpiece which has beenformed in the first press die 19 is ejected from the die by the ejector1% as soon as the punch 16 has backed into the position shown inFigure 1. At this instant the driving mechanism swivels lever 42 in thedirection of the arrow P in Figure 2. This causes the nippers 3i) and 33of the nipper arms 28 and 31 to approach one another and to grip thepressing which is emerging from the die. The cross-beam 47 is then drawnto the right, in the direction indicated by the arrow Q in Figure 4.This motion is transmitted to the nipper arms by the shafts 25 and 26.In consequence, the conveyor tongs with the nipper arms 28 and 29 movein a direction parallel to the members 14, accommodating the dies ofblock 11. This direction is to the right of Figures 1 and 4. Thedescribed motion of the conveyor tongs continues until the pressing liescoaxial with the second set of press tools, comprising punch 17 and die20. On the forward movement of the punch, the latter pushes the pressinginto the die, wherein it undergoes further forming. As the punch isbeing advanced, the nipper arms swivel apart again as illustrated inFigure 4 3 so as to clear a passage for the punch. With the nippers 30and 33 separated, beam' 47 is returned to its initial position, to theleft in Figure 4, while the pressing process is taking place. When thepressing is subsequently ejected from die 20 by ejector 29a it comeswithin range of the second pair of conveyer tongs with nipper arms 29and 32, and is carried by the same, in a similar manner, to aposition-in line with the axis of the third press die 21. As punch 18advances it pushes the pressing into the third die, where the pressingis given its final shape and from which it is then ejected by ejector210. At the same time the conveyer tongs return again to the positionsshown in Figures 1 and 4. The finished pressing drops onto a chute, notshown, which guides it into a collecting bin.

Actually the press functions in such a manner that the three punches16-18 move forward simultaneously and that the three dies each contain apressing at the same time.

The two sets of conveyor tongs with the nipper arms 28 and 31, and 29and 32 respectively, must then each seize a pressing at the same time.In the event of these pressings not having equal dimensions, the nippers30 and 33 of the tongs may have to approach each other more closely inone case than in the other, which would not be possible if the nipperarms were rigidly attached to the two shafts 25 and 26, which are commonto both pairs of nippers. This possibility has been provided for, in thecase of the press described, by means of the springs, previouslymentioned but not shown in the drawing, which render elastic theconnection between the flaps 28a and 29a of the nipper arms and theflaps 27a of coupling member 27 and, in a similar way, the connectionbetween the nipper arms 31 and 32 and the coupling member 34. Theindividual nipper arms are thus elastically secured to the shafts 25 and26 and can accordingly yield somewhat, when seizing pressings, as may berequired by the dimensions of the latter. The grip exerted by thenippers 30 and 33 is thus transmitted by means of the said springs.

The purpose of spring 43 is to take up the play in the joint 45 and inthe remainder of the transmission mechanism, not shown in the drawing,for actuating the lever 42, this mechanism being permanently subjectedto a unidirectional force exerted by spring 43.

The conveyor tongs described for the conveyance of the pressings, havethe advantage over known types that their nippers grip the pressings ina direction trans verse to that of conveyance of the latter, with theresult that only a relatively small opening or closing travel of thenippers is required. Despite the fact that several sets of conveyornippers are provided, as in the embodiment shown, it is possible todesign the press on relatively simple lines by arranging the nipper armson common shafts which rotate about their axes in contrary directionsand are at the same time axially displaceable. This construction isimposed by the use of a frame-shaped block 11, because, since themembers of the block run parallel to the direction of the press, it isimpossible to make use of the conveyor tongs otherwise customary.

A further essential advantage of the construction described lies in thefact that the mounting of the tongs is located beyond the range ofinfluence of the heat and of the scale.

In Figures 4 and 5 the coupling piece 34 is shown in cross-section. Themandrels 51 and 50 are shown in elevation and their purpose is as abovedescribed. It is understood that the splines 39 of the shafts 25 and 26are longer than the interval from one die to the next in order that thetong arms can be opened or closed during the entire longitudinalmovement of the shafts. The spline shafts do not rotate but oscillateoppositely to one another through a small angle from the ends of therevolution point so that the tong arms grip almost vertically in thefree space between the block portions 13 and 14.

The means for driving and operating the various instrumentalitiesmentioned above will now be described with particular reference toFigures 6, 7, 8 and 9.

The punch holders 65 for holding the punches 16, 1'7 and 18 sliding inthe sleeves 15 are connected to the ram 66 in known manner and the ramis reciprocated by the main crank 67 through the connecting rod 63.

A motor 69 is mounted in a cradle 70 which is pivotally connected at 71to the bed so that the tension upon the V belts 72 may be adjusted. Thebelts drive a flywheel 73 which is connected to the countershaft 74 by amultiple disc clutch not shown. The main crank 67 is driven by thepinion 1632 and the gear 103 and the longitudinally extending cam shaft75 is driven by the pinion 1194 upon the countcrshaft 74 meshing withthe gear 76 mounted upon a stub shaft which also carries the bevel gear77 which meshes with the bevel gear MP5 keyed to the cam shaft 75.

The means for operating the tongs is shown at the right of Fig. 6 and inFig. 7. This consists of a rod 62 connected pivotally to the joint 4-5and resiliently connected by means of a spring '78 to one end of adouble armed lever 79 pivoted to a stub shaft 8i which is mounted in acasing 81 secured fixedly to the bed Lid. The double armed lever 79 hassecured thereto on one arm a roller 82 and on the other arm a roller 83which cooperate with a cam 84 keyed to the cam shaft 75. The cam 84cooperating with the rollers 82 and 33 upon the lever 79 willreciprocate the arm 62 so as to bring about the proper operation of thetongs.

In Figures 8 and 9 the means for reciprocating the yoke 47 so as to movethe tongs from one die to the next and return is shown. This comprises aslot 48 provided in the yoke 47 in which a roller 35' mounted upon acrank 86 operates. The crank 85 is keyed to a stubshaft 83 upon which isalso fixed a pinion 87. The pinion ii? is oscillated through an arc of180 by means of a rack 89. The rack 89 is reciprocated by means of therollers res and 101 carried by the frame 9t) of the rack cooperatingwith the cams 91 and 92 respectively mounted upon the cam shaft 75. Arectangular member 93 is rotatably mounted also upon the cam shaft 75and slides within the frame 90 in order to secure rectilinear movementof the rack 89.

The center distance of the crank 86 is half the dis tance of one die tothe other. The stroke of the cams 9i and 92 is arranged in such a Waythat the rack 89 will revolve the pinion 87 and the crank 189 so thatthe yoke 47 will move laterally covering the distance from one die tothe next with a dwell at each end position. The dwell period isnecessary in order to permit the nippers 29 and 32 to hold the blanks infront of the dies until the respective punches introduce them therein.The dwell period is also provided so that the nippers may stay in frontof the dies in order to pick up the blanks when ejected.

The ratio of the gears 1432 and 193 is the same as the total ratio ofthe gears 104, 76, 77 and 105. Therefore the main crank shaft willrevolve at the same speed as the longitudinal cam shaft.

It is thought that the invention and its advantages will be understoodfrom the foregoing description and it is apparent that various changesmay be made in the process, form, construction and arrangement of theparts without departing from the spirit and scope of the invention orsacrificing its material advantages, the forms hereinbefore describedand illustrated in the drawings being merely preferred embodimentsthereof.

I claim:

1. A transfer mechanism for moving blanks from one station to another ina progressive press tool in order to continue the shaping of the blankin said press tool which comprises at least two dies and presses for themanufacturing of screw nuts, said transfer mechanism comprising twosubstantially right angularly bent nipper arms, a pair of shafts uponwhich said arms are secured,

each of said shafts being located on opposite sides of the tool planeand parallel thereto, means for oscillating said shafts in oppositedirections to move said nipper arms towards and away from one another sothat the nipper arms may grasp said blanks in the free space in front ofthe dies and means for reciprocating said shafts longitudinally of theiraxes to transfer said blanks from one die to another when said blanksare gripped by said nipper arms.

2. A transfer mechanism for moving blanks from one station to another ina progressive press tool in order to continue the shaping of the blankin said press tool which comprises at least two dies and presses for themanufacturing of screw nuts, said transfer mechanism comprising twosubstantially right angularly bent nipper arms, a pair of shafts uponwhich said arms are secured, each of said shafts being located onopposite sides of the tool plane and parallel thereto, a crank armsecured to each of said shafts, a pivoted double armed lever to whichsaid crank arms are connected, means for oscillating said lever tothereby oscillate said shafts in opposite directions to move said nipperarms towards and away from one another so that the nip-per arms maygrasp said blanks in the free space in front of the dies and means forreciprocatingsaid shafts longitudinally of their axes to transfer saidblanks from one die to another when said blanks are gripped by saidnipper arms.

3. A transfer mechanism for moving blanks from one station to another ina progressive press tool in order to continue the shaping of the blankin said press tool which comprises at least two dies and presses for themanufacturing of screw nuts, said transfer mechanism comprising twosubstantially right ang'ularly bent nipper arms, a pair of shafts uponwhich said arms are secured, each of said shafts being located onopposite sides of the tool plane and parallel thereto, a sleeve splinedto each of said shafts, a crank arm fixed to each sleeve, a pivoteddouble armed lever to which said crank arms are connected, areciprocating drawbar for oscillating said lever to oscillate saidshafts in opposite directions to move said nipper arms towards and awayfrom one another so that the nipper arms may grasp said blanks in thefree space in front of the dies and means for reciprocating said shaftslongitudinally of their axes to transfer said blanks from one die toanother when said blanks are gripped by said nipper arms.

4. A. transfer mechanism for moving blanks from one station to anotherin a progressive press tool in order to continue the shaping of theblank in said press tool which comprises at least two dies and pressesfor the manufacturing of screw nuts, said transfer mechanism comprisingtwo substantially right angularly bent nipper arms, a pair or" shaftsupon which said arms are secured, each of said shafts being located onopposite sides of the tool plane and parallel thereto, means foroscillating said shafts in opposite directions to move said nipper armstowards and away from one another so that the nipper arms may grasp saidblanks in the free space in front of the dies, a yoke interconnectingsaid shafts and means cooperating with said yoke to reciprocate the sameand thereby move said shafts longitudinally of their axes to transfersaid blanks from one die to another when said blanks are gripped by saidnipper arms.

5. A transfer mechanism as set forth in claim 4, wherein said meanscooperating with said yoke comprises a cam operated rack bar, a gearcooperating with said rack bar and an oscillating lever attached to saidgear.

References Cited in the file of this patent UNITED STATES PATENTS 46,434Watkins Feb. 14, 1865 2,124,113 Kaufman July 19, 1938 2,326,588 WalesAug. 10, 1943 2,527,091 Carrier Oct. 24, 1950

